<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Post请求</title>
    <style>
        #result {
            width: 200px;
            height: 180px;
            border: 1px solid blue;
        }
    </style>
</head>
<body>
    <div id="result">

    </div>
    <script>
        const result = document.getElementById('result');
        result.addEventListener('mouseover', function() {
            //创建对象
            const xhr = new XMLHttpRequest();
            //初始化 设置类型与url
            xhr.open('POST', 'http://127.0.0.1:8000/server');
            //设置请求头
            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
            //发送
            xhr.send();
            //事件绑定
            xhr.onreadystatechange = function() {
                if(xhr.readyState === 4) {
                    if(xhr.status >= 200 && xhr.status < 300) {
                        result.innerHTML = xhr.response;
                    }
                }
            }
        })
    </script>
</body>
</html>